object - Can Java cast anything? -


i've taken year of java course @ school , understanding of casting pretty limited.

the type of casting understand casting int double. makes sense; 1 become 1.0

the type of casting don't quite understand is: casting custom object (say superrectangle) customer object (eg, myrectangle). (this assuming myrectangle subclass of superrectangle) happens private or public fields associated instance of superrectangle? how program know legit move? matters could've casted int string, , supposed mean anyway?

strictly speaking, going int double isn't casting, conversion. casting reinterpreting same, unchanged bit pattern in memory belonging type. , precisely casting reference types in java boils down to: have object of definite, unchangeable type, , merely look @ if instance of 1 of supertypes.

you not allowed cast integer string because latter not former's supertype. ensured @ compile time , double-checked @ runtime well.


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